A Docker security update has been released for Ubuntu Linux 16.04 LTS, 18.04 LTS, and 20.04 LTS.

USN-4589-2: Docker vulnerability

=========================================================================
Ubuntu Security Notice USN-4589-2
October 15, 2020

docker.io vulnerability
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

Docker could be made to expose sensitive information over the
network.

Software Description:
- docker.io: Linux container runtime

Details:

USN-4589-1 fixed a vulnerability in containerd. This update provides
the corresponding update for docker.io.

Original advisory details:

It was discovered that containerd could be made to expose sensitive
information when processing URLs in container image manifests. A
remote attacker could use this to trick the user and obtain the
user's registry credentials.

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 20.04 LTS:
docker.io 19.03.8-0ubuntu1.20.04.1

Ubuntu 18.04 LTS:
docker.io 19.03.6-0ubuntu1~18.04.2

Ubuntu 16.04 LTS:
docker.io 18.09.7-0ubuntu1~16.04.6

After a standard system update you need to restart docker to make
all the necessary changes.

References:
  https://usn.ubuntu.com/4589-2
  https://usn.ubuntu.com/4589-1
CVE-2020-15157

Package Information:
  https://launchpad.net/ubuntu/+source/docker.io/19.03.8-0ubuntu1.20.04.1
  https://launchpad.net/ubuntu/+source/docker.io/19.03.6-0ubuntu1~18.04.2
  https://launchpad.net/ubuntu/+source/docker.io/18.09.7-0ubuntu1~16.04.6